Patchers are well known in the field for repairing potholes and the like. Conventional patchers are typically provided with emulsion and aggregate tanks and the means for conveying their contents, either selectively or in combination to dispensing apparatus. For example, Applicant's U.S. Pat. No. 7,544,253, issued Jun. 9, 2009, teaches self-propelled patcher apparatus having the above-mentioned capabilities and is incorporated herein by reference.
In order to dispense aggregate in a positive and highly efficient manner by use of air pressure, it is necessary to be able to pressurize the aggregate tank, necessitating the provision of an air-tight seal. Air tight seals for tanks used to store and deliver liquids, such as an emulsion employed in patching operations, typically have a relatively small opening relative to the overall size of the tank storing the emulsion so that the closure for air tightly sealing the opening provided to deliver fresh emulsion into the tank is quite simple in design and yet quite effective in providing the necessary air tight seal.
In contrast, it is necessary to provide a large opening in order to rapidly and efficiently feed fresh aggregate into the aggregate tank. This is typically accomplished by providing a large opening sealed by a lid typically pivotally mounted to the top of the aggregate tank. It is conventional to provide a gasket for sealing the mating surfaces of the lid and the top lip of the opening in the aggregate tank to provide an adequate air-tight seal.
Manually operable clamping devices have typically been used in conventional systems. However, this necessitates providing a number of independent clamping devices at spaced locations about the aggregate tank lid, necessitating multiple manual operations when opening and closing the tank lid. It is, therefore, one objective of the present invention to provide clamping apparatus for automatically and simultaneously clamping and unclamping the aggregate tank lid to achieve an air-tight seal through a single opening or closing operation.
Another objective of the present invention is to provide a drive source which automatically closes the aggregate tank lid and, upon closure, automatically clamps the aggregate tank lid to assure an air-tight seal responsive to the lid reaching the closed position.
Still another objective of the present invention is to provide a novel actuator mechanism for opening and closing the aggregate tank outlet opening through the utilization of first and second linear accelerators arranged in tandem to provide opening and closing control, as well as a regulating the size of the opening to control rate of flow of aggregate.
Utilization of electrically powered linear accelerators opening in tandem enables operation of the patcher vehicle using exclusively electric power during a patching mode, including movement of the patcher vehicle during the patching mode.